In a combustion turbine engine, which may include power generating, aircraft or other engine types, pressurized air is used to combust a fuel to generate a flow of hot combustion gases, which is then directed through one or more turbines that extract energy. In the turbine, rows of circumferentially spaced turbine rotor blades extend radially outwardly from a supporting rotor disc. Each blade typically includes a dovetail that permits assembly and disassembly of the blade in a corresponding dovetail slot in the rotor disc, as well as an airfoil that extends radially outwardly from the dovetail and interacts with the flow of the working fluid through the engine. The airfoil has a pressure side and suction side extending axially between corresponding leading and trailing edges and radially between a root portion and a tip portion. The blade tip may include a radially outer turbine shroud to minimize leakage of the combustion gases flowing downstream between the turbine blades.
Ceramic matrix composite (CMC) materials can sustain higher temperatures than traditional metal alloys, and can be used in turbine engines where higher fuel efficiencies can be attained with higher temperatures. The amount of cooling air required to operate a metal component can be reduced when a CMC component is used. In addition, CMC materials are less dense that metals, which can provide weight savings and improve fuel efficiency.